source3/smbd/scavenger.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    smbd scavenger daemon
   4
   5    Copyright (C) Gregor Beck                    2013
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22
  23 #include "messages.h"
  24 #include "serverid.h"
  25 #include "smbd/globals.h"
  26 #include "smbd/scavenger.h"
  27 #include "locking/proto.h"
  28 #include "lib/util/util_process.h"
  29 #include "lib/sys_rw.h"
  30
  31 #undef DBGC_CLASS
  32 #define DBGC_CLASS DBGC_SCAVENGER
  33
  34 struct smbd_scavenger_state {
  35         struct tevent_context *ev;
  36         struct messaging_context *msg;
  37         struct server_id parent_id;
  38         struct server_id *scavenger_id;
  39         bool am_scavenger;
  40 };
  41
  42 static struct smbd_scavenger_state *smbd_scavenger_state = NULL;
  43
  44 struct scavenger_message {
  45         struct file_id file_id;
  46         uint64_t open_persistent_id;
  47         NTTIME until;
  48 };
  49
  50 static int smbd_scavenger_main(struct smbd_scavenger_state *state)
  51 {
  52         struct server_id_buf tmp1, tmp2;
  53
  54         DEBUG(10, ("scavenger: %s started, parent: %s\n",
  55                    server_id_str_buf(*state->scavenger_id, &tmp1),
  56                    server_id_str_buf(state->parent_id, &tmp2)));
  57
  58         while (true) {
  59                 TALLOC_CTX *frame = talloc_stackframe();
  60                 int ret;
  61
  62                 ret = tevent_loop_once(state->ev);
  63                 if (ret != 0) {
  64                         DEBUG(2, ("tevent_loop_once failed: %s\n",
  65                                   strerror(errno)));
  66                         TALLOC_FREE(frame);
  67                         return 1;
  68                 }
  69
  70                 DEBUG(10, ("scavenger: %s event loop iteration\n",
  71                            server_id_str_buf(*state->scavenger_id, &tmp1)));
  72                 TALLOC_FREE(frame);
  73         }
  74
  75         return 0;
  76 }
  77
  78 static void smbd_scavenger_done(struct tevent_context *event_ctx, struct tevent_fd *fde,
  79                                 uint16_t flags, void *private_data)
  80 {
  81         struct smbd_scavenger_state *state = talloc_get_type_abort(
  82                 private_data, struct smbd_scavenger_state);
  83         struct server_id_buf tmp;
  84
  85         DEBUG(2, ("scavenger: %s died\n",
  86                   server_id_str_buf(*state->scavenger_id, &tmp)));
  87
  88         TALLOC_FREE(state->scavenger_id);
  89 }
  90
  91 static void smbd_scavenger_parent_dead(struct tevent_context *event_ctx,
  92                                        struct tevent_fd *fde,
  93                                        uint16_t flags, void *private_data)
  94 {
  95         struct smbd_scavenger_state *state = talloc_get_type_abort(
  96                 private_data, struct smbd_scavenger_state);
  97         struct server_id_buf tmp1, tmp2;
  98
  99         DEBUG(2, ("scavenger: %s parent %s died\n",
 100                   server_id_str_buf(*state->scavenger_id, &tmp1),
 101                   server_id_str_buf(state->parent_id, &tmp2)));
 102
 103         exit_server("smbd_scavenger_parent_dead");
 104 }
 105
 106 static void scavenger_sig_term_handler(struct tevent_context *ev,
 107                                        struct tevent_signal *se,
 108                                        int signum,
 109                                        int count,
 110                                        void *siginfo,
 111                                        void *private_data)
 112 {
 113         exit_server_cleanly("termination signal");
 114 }
 115
 116 static void scavenger_setup_sig_term_handler(struct tevent_context *ev_ctx)
 117 {
 118         struct tevent_signal *se;
 119
 120         se = tevent_add_signal(ev_ctx,
 121                                ev_ctx,
 122                                SIGTERM, 0,
 123                                scavenger_sig_term_handler,
 124                                NULL);
 125         if (se == NULL) {
 126                 exit_server("failed to setup SIGTERM handler");
 127         }
 128 }
 129
 130 static bool smbd_scavenger_running(struct smbd_scavenger_state *state)
 131 {
 132         if (state->scavenger_id == NULL) {
 133                 return false;
 134         }
 135
 136         return serverid_exists(state->scavenger_id);
 137 }
 138
 139 static int smbd_scavenger_server_id_destructor(struct server_id *id)
 140 {
 141         serverid_deregister(*id);
 142         return 0;
 143 }
 144
 145 static bool scavenger_say_hello(int fd, struct server_id self)
 146 {
 147         const uint8_t *msg = (const uint8_t *)&self;
 148         size_t remaining = sizeof(self);
 149         size_t ofs = 0;
 150         struct server_id_buf tmp;
 151
 152         while (remaining > 0) {
 153                 ssize_t ret;
 154
 155                 ret = sys_write(fd, msg + ofs, remaining);
 156                 if (ret == -1) {
 157                         DEBUG(2, ("Failed to write to pipe: %s\n",
 158                                   strerror(errno)));
 159                         return false;
 160                 }
 161                 remaining -= ret;
 162         }
 163
 164         DEBUG(4, ("scavenger_say_hello: self[%s]\n",
 165                   server_id_str_buf(self, &tmp)));
 166         return true;
 167 }
 168
 169 static bool scavenger_wait_hello(int fd, struct server_id *child)
 170 {
 171         uint8_t *msg = (uint8_t *)child;
 172         size_t remaining = sizeof(*child);
 173         size_t ofs = 0;
 174         struct server_id_buf tmp;
 175
 176         while (remaining > 0) {
 177                 ssize_t ret;
 178
 179                 ret = sys_read(fd, msg + ofs, remaining);
 180                 if (ret == -1) {
 181                         DEBUG(2, ("Failed to read from pipe: %s\n",
 182                                   strerror(errno)));
 183                         return false;
 184                 }
 185                 remaining -= ret;
 186         }
 187
 188         DEBUG(4, ("scavenger_say_hello: child[%s]\n",
 189                   server_id_str_buf(*child, &tmp)));
 190         return true;
 191 }
 192
 193 static bool smbd_scavenger_start(struct smbd_scavenger_state *state)
 194 {
 195         struct server_id self = messaging_server_id(state->msg);
 196         struct tevent_fd *fde = NULL;
 197         int fds[2];
 198         int ret;
 199         uint64_t unique_id;
 200         bool ok;
 201
 202         SMB_ASSERT(server_id_equal(&state->parent_id, &self));
 203
 204         if (smbd_scavenger_running(state)) {
 205                 struct server_id_buf tmp;
 206                 DEBUG(10, ("scavenger %s already running\n",
 207                            server_id_str_buf(*state->scavenger_id,
 208                                              &tmp)));
 209                 return true;
 210         }
 211
 212         if (state->scavenger_id != NULL) {
 213                 struct server_id_buf tmp;
 214                 DEBUG(10, ("scavenger zombie %s, cleaning up\n",
 215                            server_id_str_buf(*state->scavenger_id,
 216                                              &tmp)));
 217                 TALLOC_FREE(state->scavenger_id);
 218         }
 219
 220         state->scavenger_id = talloc_zero(state, struct server_id);
 221         if (state->scavenger_id == NULL) {
 222                 DEBUG(2, ("Out of memory\n"));
 223                 goto fail;
 224         }
 225         talloc_set_destructor(state->scavenger_id,
 226                               smbd_scavenger_server_id_destructor);
 227
 228         ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
 229         if (ret == -1) {
 230                 DEBUG(2, ("socketpair failed: %s", strerror(errno)));
 231                 goto fail;
 232         }
 233
 234         smb_set_close_on_exec(fds[0]);
 235         smb_set_close_on_exec(fds[1]);
 236
 237         unique_id = serverid_get_random_unique_id();
 238
 239         ret = fork();
 240         if (ret == -1) {
 241                 int err = errno;
 242                 close(fds[0]);
 243                 close(fds[1]);
 244                 DEBUG(0, ("fork failed: %s", strerror(err)));
 245                 goto fail;
 246         }
 247
 248         if (ret == 0) {
 249                 /* child */
 250
 251                 NTSTATUS status;
 252
 253                 close(fds[0]);
 254
 255                 set_my_unique_id(unique_id);
 256
 257                 status = smbd_reinit_after_fork(state->msg, state->ev, true);
 258                 if (!NT_STATUS_IS_OK(status)) {
 259                         DEBUG(2, ("reinit_after_fork failed: %s\n",
 260                                   nt_errstr(status)));
 261                         exit_server("reinit_after_fork failed");
 262                         return false;
 263                 }
 264
 265                 prctl_set_comment("smbd-scavenger");
 266
 267                 state->am_scavenger = true;
 268                 *state->scavenger_id = messaging_server_id(state->msg);
 269
 270                 scavenger_setup_sig_term_handler(state->ev);
 271
 272                 if (!serverid_register(*state->scavenger_id,
 273                                        FLAG_MSG_GENERAL)) {
 274                         DBG_WARNING("serverid_register failed");
 275                         exit_server("serverid_register failed");
 276                         return false;
 277                 }
 278
 279                 ok = scavenger_say_hello(fds[1], *state->scavenger_id);
 280                 if (!ok) {
 281                         DEBUG(2, ("scavenger_say_hello failed\n"));
 282                         exit_server("scavenger_say_hello failed");
 283                         return false;
 284                 }
 285
 286                 fde = tevent_add_fd(state->ev, state->scavenger_id,
 287                                     fds[1], TEVENT_FD_READ,
 288                                     smbd_scavenger_parent_dead, state);
 289                 if (fde == NULL) {
 290                         DEBUG(2, ("tevent_add_fd(smbd_scavenger_parent_dead) "
 291                                   "failed\n"));
 292                         exit_server("tevent_add_fd(smbd_scavenger_parent_dead) "
 293                                     "failed");
 294                         return false;
 295                 }
 296                 tevent_fd_set_auto_close(fde);
 297
 298                 ret = smbd_scavenger_main(state);
 299
 300                 DEBUG(10, ("scavenger ended: %d\n", ret));
 301                 exit_server_cleanly("scavenger ended");
 302                 return false;
 303         }
 304
 305         /* parent */
 306         close(fds[1]);
 307
 308         ok = scavenger_wait_hello(fds[0], state->scavenger_id);
 309         if (!ok) {
 310                 close(fds[0]);
 311                 goto fail;
 312         }
 313
 314         fde = tevent_add_fd(state->ev, state->scavenger_id,
 315                             fds[0], TEVENT_FD_READ,
 316                             smbd_scavenger_done, state);
 317         if (fde == NULL) {
 318                 close(fds[0]);
 319                 goto fail;
 320         }
 321         tevent_fd_set_auto_close(fde);
 322
 323         return true;
 324 fail:
 325         TALLOC_FREE(state->scavenger_id);
 326         return false;
 327 }
 328
 329 static void scavenger_add_timer(struct smbd_scavenger_state *state,
 330                                 struct scavenger_message *msg);
 331
 332 static void smbd_scavenger_msg(struct messaging_context *msg_ctx,
 333                                void *private_data,
 334                                uint32_t msg_type,
 335                                struct server_id src,
 336                                DATA_BLOB *data)
 337 {
 338         struct smbd_scavenger_state *state =
 339                 talloc_get_type_abort(private_data,
 340                                       struct smbd_scavenger_state);
 341         TALLOC_CTX *frame = talloc_stackframe();
 342         struct server_id self = messaging_server_id(msg_ctx);
 343         struct scavenger_message *msg = NULL;
 344         struct server_id_buf tmp1, tmp2;
 345
 346         DEBUG(10, ("smbd_scavenger_msg: %s got message from %s\n",
 347                    server_id_str_buf(self, &tmp1),
 348                    server_id_str_buf(src, &tmp2)));
 349
 350         if (server_id_equal(&state->parent_id, &self)) {
 351                 NTSTATUS status;
 352
 353                 if (!smbd_scavenger_running(state) &&
 354                     !smbd_scavenger_start(state))
 355                 {
 356                         DEBUG(2, ("Failed to start scavenger\n"));
 357                         goto done;
 358                 }
 359                 DEBUG(10, ("forwarding message to scavenger\n"));
 360
 361                 status = messaging_send(msg_ctx,
 362                                         *state->scavenger_id, msg_type, data);
 363                 if (!NT_STATUS_IS_OK(status)) {
 364                         DEBUG(2, ("forwarding message to scavenger failed: "
 365                                   "%s\n", nt_errstr(status)));
 366                         goto done;
 367                 }
 368                 goto done;
 369         }
 370
 371         if (!state->am_scavenger) {
 372                 DEBUG(10, ("im not the scavenger: ignore message\n"));
 373                 goto done;
 374         }
 375
 376         if (!server_id_equal(&state->parent_id, &src)) {
 377                 DEBUG(10, ("scavenger: ignore spurious message\n"));
 378                 goto done;
 379         }
 380
 381         DEBUG(10, ("scavenger: got a message\n"));
 382         msg = (struct scavenger_message*)data->data;
 383         scavenger_add_timer(state, msg);
 384 done:
 385         talloc_free(frame);
 386 }
 387
 388 bool smbd_scavenger_init(TALLOC_CTX *mem_ctx,
 389                          struct messaging_context *msg,
 390                          struct tevent_context *ev)
 391 {
 392         struct smbd_scavenger_state *state;
 393         NTSTATUS status;
 394
 395         if (smbd_scavenger_state) {
 396                 DEBUG(10, ("smbd_scavenger_init called again\n"));
 397                 return true;
 398         }
 399
 400         state = talloc_zero(mem_ctx, struct smbd_scavenger_state);
 401         if (state == NULL) {
 402                 DEBUG(2, ("Out of memory\n"));
 403                 return false;
 404         }
 405
 406         state->msg = msg;
 407         state->ev = ev;
 408         state->parent_id = messaging_server_id(msg);
 409
 410         status = messaging_register(msg, state, MSG_SMB_SCAVENGER,
 411                                     smbd_scavenger_msg);
 412         if (!NT_STATUS_IS_OK(status)) {
 413                 DEBUG(2, ("failed to register message handler: %s\n",
 414                           nt_errstr(status)));
 415                 goto fail;
 416         }
 417
 418         smbd_scavenger_state = state;
 419         return true;
 420 fail:
 421         talloc_free(state);
 422         return false;
 423 }
 424
 425 void scavenger_schedule_disconnected(struct files_struct *fsp)
 426 {
 427         NTSTATUS status;
 428         struct server_id self = messaging_server_id(fsp->conn->sconn->msg_ctx);
 429         struct timeval disconnect_time, until;
 430         uint64_t timeout_usec;
 431         struct scavenger_message msg;
 432         DATA_BLOB msg_blob;
 433         struct server_id_buf tmp;
 434
 435         if (fsp->op == NULL) {
 436                 return;
 437         }
 438         nttime_to_timeval(&disconnect_time, fsp->op->global->disconnect_time);
 439         timeout_usec = 1000 * fsp->op->global->durable_timeout_msec;
 440         until = timeval_add(&disconnect_time,
 441                             timeout_usec / 1000000,
 442                             timeout_usec % 1000000);
 443
 444         ZERO_STRUCT(msg);
 445         msg.file_id = fsp->file_id;
 446         msg.open_persistent_id = fsp->op->global->open_persistent_id;
 447         msg.until = timeval_to_nttime(&until);
 448
 449         DEBUG(10, ("smbd: %s mark file %s as disconnected at %s with timeout "
 450                    "at %s in %fs\n",
 451                    server_id_str_buf(self, &tmp),
 452                    file_id_string_tos(&fsp->file_id),
 453                    timeval_string(talloc_tos(), &disconnect_time, true),
 454                    timeval_string(talloc_tos(), &until, true),
 455                    fsp->op->global->durable_timeout_msec/1000.0));
 456
 457         SMB_ASSERT(server_id_is_disconnected(&fsp->op->global->server_id));
 458         SMB_ASSERT(!server_id_equal(&self, &smbd_scavenger_state->parent_id));
 459         SMB_ASSERT(!smbd_scavenger_state->am_scavenger);
 460
 461         msg_blob = data_blob_const(&msg, sizeof(msg));
 462         DEBUG(10, ("send message to scavenger\n"));
 463
 464         status = messaging_send(smbd_scavenger_state->msg,
 465                                 smbd_scavenger_state->parent_id,
 466                                 MSG_SMB_SCAVENGER,
 467                                 &msg_blob);
 468         if (!NT_STATUS_IS_OK(status)) {
 469                 struct server_id_buf tmp1, tmp2;
 470                 DEBUG(2, ("Failed to send message to parent smbd %s "
 471                           "from %s: %s\n",
 472                           server_id_str_buf(smbd_scavenger_state->parent_id,
 473                                             &tmp1),
 474                           server_id_str_buf(self, &tmp2),
 475                           nt_errstr(status)));
 476         }
 477 }
 478
 479 struct scavenger_timer_context {
 480         struct smbd_scavenger_state *state;
 481         struct scavenger_message msg;
 482 };
 483
 484 static void scavenger_timer(struct tevent_context *ev,
 485                             struct tevent_timer *te,
 486                             struct timeval t, void *data)
 487 {
 488         struct scavenger_timer_context *ctx =
 489                 talloc_get_type_abort(data, struct scavenger_timer_context);
 490         NTSTATUS status;
 491         bool ok;
 492
 493         DEBUG(10, ("scavenger: do cleanup for file %s at %s\n",
 494                   file_id_string_tos(&ctx->msg.file_id),
 495                   timeval_string(talloc_tos(), &t, true)));
 496
 497         ok = share_mode_cleanup_disconnected(ctx->msg.file_id,
 498                                              ctx->msg.open_persistent_id);
 499         if (!ok) {
 500                 DEBUG(2, ("Failed to cleanup share modes and byte range locks "
 501                           "for file %s open %llu\n",
 502                           file_id_string_tos(&ctx->msg.file_id),
 503                           (unsigned long long)ctx->msg.open_persistent_id));
 504         }
 505
 506         status = smbXsrv_open_cleanup(ctx->msg.open_persistent_id);
 507         if (!NT_STATUS_IS_OK(status)) {
 508                 DEBUG(2, ("Failed to cleanup open global for file %s open %llu:"
 509                           " %s\n", file_id_string_tos(&ctx->msg.file_id),
 510                           (unsigned long long)ctx->msg.open_persistent_id,
 511                           nt_errstr(status)));
 512         }
 513 }
 514
 515 static void scavenger_add_timer(struct smbd_scavenger_state *state,
 516                                 struct scavenger_message *msg)
 517 {
 518         struct tevent_timer *te;
 519         struct scavenger_timer_context *ctx;
 520         struct timeval until;
 521
 522         nttime_to_timeval(&until, msg->until);
 523
 524         DEBUG(10, ("scavenger: schedule file %s for cleanup at %s\n",
 525                    file_id_string_tos(&msg->file_id),
 526                    timeval_string(talloc_tos(), &until, true)));
 527
 528         ctx = talloc_zero(state, struct scavenger_timer_context);
 529         if (ctx == NULL) {
 530                 DEBUG(2, ("Failed to talloc_zero(scavenger_timer_context)\n"));
 531                 return;
 532         }
 533
 534         ctx->state = state;
 535         ctx->msg = *msg;
 536
 537         te = tevent_add_timer(state->ev,
 538                               state,
 539                               until,
 540                               scavenger_timer,
 541                               ctx);
 542         if (te == NULL) {
 543                 DEBUG(2, ("Failed to add scavenger_timer event\n"));
 544                 talloc_free(ctx);
 545                 return;
 546         }
 547
 548         /* delete context after handler was running */
 549         talloc_steal(te, ctx);
 550 }